The Aims of Resource Core A ? the Tissue Processing and Histology Core ? are to enable and enhance the speed and efficiency of skin research and to provide unique expertise and access to tissue and reagents for research in cutaneous biology and diseases to those both within and outside the field. In order to accomplish these Aims, Core A will provide the following services: (1) Expert service and training in the processing, embedding, sectioning, and staining of skin specimens from humans and animals; (2) Expert service and training in immunohistochemical/immunofluorescence staining for proteins in skin samples and development of staining protocols for new antibodies; (3) Clinical and scientific expertise, administrative support, and service for obtaining formalin-fixed sections of normal and diseased human skin; (4) Expert service in laser capture microdissection (LCM) of skin sections for molecular and genomic analysis; (5) Expert microscopic interpretation and evaluation of animal and human skin histology to ensure accurate correlation between human diseases and animal model phenotypes. Tissue processing, histology and immunostaining services specific for cutaneous samples are not available elsewhere on Penn's campus. Setting up such services in individual labs would be time consuming and expensive, and unlikely to yield the high quality specimens produced by this Core. Core A therefore facilitates a broad range of research in animal models and human patients. Core A also provides access to a unique archive of human formalin-fixed skin tissue blocks containing approximately 1.8 million samples that represent a diverse range of even rare skin disease diagnoses. These specimens, coupled with searchable database capability, constitute an outstanding resource for skin disease researchers. Using current technology, formalin-fixed tissue samples represent a key resource in defining the molecular and genomic features of human skin diseases. Core A provides specific expertise in state-of-the-art laser capture microdissection of skin, including using samples from the Core A archive, for genomics analyses including exome sequencing, RNA-seq and ChIP-seq. Finally, Core A provides access to consultation with Dr. John Seykora, who has unique expertise in the dermatopathology of human and mouse skin tissue, and Dr. Elizabeth Maudlin, an expert veterinary dermatopathologist. Together, these services will help SBDRC members achieve our overall goals of supporting basic research and promoting its translation to clinical practice by providing: (i) analysis of human patient as well as animal model tissue; (ii) access to expertise in both human and animal dermatopathology, allowing accurate assessment of the relevance of particular animal models to specific human diseases.